Using VSEPR Theory, predict the electron-pair geometry and the molecular geometry of CO2. a. linear, bent b. tetrahedral, tetrahedral c. bent, linear d. linear, linear
The Correct Answer and Explanation is:
The correct answer is d. linear, linear.
Explanation:
To predict the electron-pair geometry and the molecular geometry of CO2 (carbon dioxide) using VSEPR (Valence Shell Electron Pair Repulsion) theory, we follow these steps:
- Determine the Lewis structure of CO2:
- Carbon (C) has 4 valence electrons, and each oxygen (O) atom has 6 valence electrons, for a total of 16 valence electrons in CO2.
- The Lewis structure shows a central carbon atom double-bonded to two oxygen atoms, with each oxygen having two lone pairs.
- Electron-pair geometry:
- The central atom, carbon, is surrounded by two regions of electron density (the two double bonds to oxygen). In VSEPR theory, two regions of electron density around a central atom lead to a linear electron-pair geometry.
- Molecular geometry:
- The molecular geometry depends on the arrangement of atoms, not electron pairs. Since there are two atoms (oxygen) bonded to the central atom (carbon) in a straight line, the molecular geometry of CO2 is also linear.
- Bond angles:
- For a linear geometry, the bond angle between the oxygen atoms is 180°, which is typical for molecules with a linear structure like CO2.
Thus, both the electron-pair geometry and molecular geometry of CO2 are linear, making option (d) the correct choice.
In summary:
- Electron-pair geometry: linear (two regions of electron density around carbon).
- Molecular geometry: linear (atoms are arranged in a straight line).
